Time's Arrow and Eddington's Challenge

For many years, physicists and philosophers have understood that there is no sign of a fundamental "arrow" or "flow" of time in fundamental physics, and that the very idea of such a thing is problematic, for logical reasons. (How fast would time flow, for example?) Yet the human sense that time passes is so pervasive that many physicists and some philosophers remain convinced that our present physics is missing something. Sir Arthur Eddington, who invented the term "the arrow of time", was one physicist who saw these issues particularly clearly. He opted, reluctantly, for the view that there is a flow of time, missing from current physics, and issued a challenge to the opposing view that remains valid to this day. Eddington made the wrong call, in my view, but his challenge is right on the mark, and deserves to be better known.